1. Field of the Invention
This invention relates to a regulator valve for maintaining a designated gas pressure at an output thereof, and more particularly to a regulator valve that maintains a preset gas pressure and a set maximum flow rate in a device such as a transportable container for potable liquids.
3. Discussion of the Related Art
Diaphragm operated regulator valves have been utilized to regulate the flow of compressed gas applied to a gas layer on top of liquids in a storage container and to other low pressure applications. The gas is normally a non-flammable gas, such as carbon dioxide and/or nitrogen. One such regulator valve is disclosed in U.S. Pat. No. 5,238,021, dated Aug. 24, 1993. In this valve, pressure flow is regulated via a diaphragm actuator. The diaphragm actuator is 1) relatively large, 2) very costly to manufacture, and 3) unsuitable in some applications of portable storage container operations. In addition, because regulator valves of this general type are no more than a poppet valve with a control spring, they cannot be changed to different flow rates without being re-manufactured. They also move open abruptly from a fully losed position to a fully-open position and, therefore, cannot transition smoothly from a closed position to an open position and cannot achieve a flow rate therethrough that is proportional to the amount of valve opening.